Twitter's new Vine video sharing service has been hit with a number of glitches on launch day, reports AllThingsD. The most critical is a security issue which is accidentally logging some people into other users' accounts, letting them post under those identities and see any private profile information. It's unknown how many people may be experiencing the bug, but it should be possible to log back into the right account after relaunching the iPhone app.

Twitter has also temporarily disabled Facebook and Twitter sharing; some people, meanwhile, say they are unable to sign into Vine through their Twitter account, as they should be able to. Twitter has yet to respond to these two problems, but a spokesperson claims that the company is already at work on fixing switched accounts.